"Har du haft god erfaring med det?"

Translation: Have you had good experience with it?

[Martinsspiegel]

In English, it needs to be either "a good experience" or "good experiences." Just "good experience" does not work.

[FyodorPavlovich]

I'm not so sure. We can certainly say: 'I have had experience with it'. While I haven't had occasion to replace 'experience' with 'good experience', I have used 'significant experience'.

[londoncallling]

I'd say 'do you have good experience' or 'are you experienced'. I don't think erfaring is the type of experience you can have in the plural.

[Boesvig]

"Erfaring" certainly works in plural too. Eg., "det har jeg gode erfaringer med".

[Mia.Ni]

Wasn't there another word for experience? Something like oplevelse?

[ycUvuSap]

Yes. Erfaring: https://ordnet.dk/ddo/ordbog?query=erfaring

Oplevelse: https://ordnet.dk/ddo/ordbog?query=oplevelse